Improvement in artificial legs



J. C ONDELL. ARTIFICIAL LEG,

'Na 48,660. Patented July 11, 1865.

UNITEDr STATES PATENT OEEICE.

JOHN CONDELL, OF MORRISTOWN, NEW YORK.

IMPROVEMENT IN ARTIFICIAL LEGS.

Specification forming part of Letters Patent No. 48,660, dated July 1l, 1865.

To all rwhom -it may concerne,

Be it known that I ,SOHN GONDELL, ot' Morristown, in the county of St. Lawrence and State ot' New York, have made certain new and useful Improvements in Artificial Legs; and I dollereby declare the following to be afull, clear, and exact description ofthe same, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a longitudinal vertical section of the leg in a-line from iront to back as worn. Fig.2 is a vertical section of the knee-joint and the parts immediately adjacent in a line from right to left as worn. Fig. 3 isan elevation of the socket or thiglrpiece, which contains the Stump, and showing the straps by which the artificial leg is held up to its position on the wearer. -Fig. 4 is a view ot' the yoke and belts which pass around the trunk of the wearer and are secured to the straps on the socket. Figs. 5 and G show the appearance of the yoke and straps by which the artificial limb is supported ou the wearer.

Similar letters of reference indicate corresponding parts in the several tigures.

l claim to secure lightness, easy and noiseless motion, durability, and, as nearly as pos sible,'an actual adherence to the natural appearance in tlexurc and extension.

The special points of improvement will be detailed, and, beginning with the superior portion, consist, lrst, in the method of' adjust-ing the interior ot the socket to the size of the stump; second, in the peculiar structure ofthe knee-joint and the devices for supporting the articulating bolt; third, the bridge-piece, the forward end ol' which is supported in a mortisc in the frame,1hc other end being supported by the knee-joint bolt, the said bridge being the superior point of attachment for the estensorspring; fourth, in the arrangement and adaptation ofthe ham-strings, which limit the forward motidn of the leg; ifth, in the elastic attachment, which has its superior insertion at the bridge over the kneejoiut, a ud., passing t'orward or the ankle-joint and under the instep, has its inferior attachment in the toepiece; sixth, in the improved construction of the ankle-joint, where-iu the cotis attached to the lower leg by means o a balllieint. whose socket is in the foot; seventh, in the adaptation and spring attachment of the heelcord; eighth, in

the adjustment and adaptation ot' the straps which connect the artificial limb with the snspensory-yoke; ninth,intheyoke orstrap,which is so constructed as to bear upon'the trunk and form a means of suspension for the limb.

To enable others skilled in the art to which my invention appertains to fully understand and use the same, I will proceed to descrbeits construction and operation.

A is the thigh or socket in which the stump ot the limb is inserted. This socket is lined and padded, so as to give a soft and yielding` surface to the stump. For the purpose ot adjustiug its capacity to the size of the stump it is provided with a plate, B, attached to the posterior upper edge and capable of being brought forward by drawing upon a strap, C, whichI is secured at the required tension by strings D, or otherwise. By this mea-nsthc stump may be inserted and the plate B atterward fitted to the posterior portion ot'the thigh,

so as to bring the required pressure upon it to' hold it comfortably and give the stump the re- .qnisite command of the artificial limb. This is much better and more comfortable to the wearer than thrusting the stump down into asocket of the requisite tightness, as by the latter operation the skin ofthe stump is stretched and pushed up, which causes irritation. Another benefit derived from this is that as the stump shrinks and reduces in size the socket may be adjusted to tit it by the wearer himself.

The thigh is attached to the leg E by means ot' an articulating bolt or pintle, F, which I make hollow, and which passes through the sides of thc frame G of the thigh, and also through the eyes of the metallic straps H H, which are iirmly attached to the sides of the leg. (See Fig. 2.) at this point, so as to afford a good bearingsurface on the bolt which sustains the weight of the person. 4

The required degree ot' rigidity ofthe kneejoint is. obtained by screwing up the bolt F, so as to make the motion under the influence ot' the stump and the spring more or less easy, so as to move with the required flexibility, rcsembling as nearly as possible the natural motion-that is, to throw forward or backward with an easy gentle motion, which is pleasant to the wearer, and graceful as it approximates to th'c zxatural.

The frame G is made thick is located. y is limited by'other means, which remain to be This description, i'n connection with the 4drawings may be considered sutiiciently explanatory of the method ot' pivoting the thigh and leg together, but the relative motions of the parts are induced, iniiuenced, or controlled by a spring-extensor, I, and hamstrings N N, which I will proceed to describe.

The spring-extensor consists of the springr portion I, which nia-y be considered thc mus-v cular contractile portion, and the tendons 'i'- and i,'the former of which receives its insertion in the bridge-piece K, which is a block supported at two points. Its forward end is inserted into a mortise in the\frame G ot' the thigh, as is clearly shown in Fig. l, and its rearward end is supported by lapping upon the bolt F, the under sideot' the bridge-piece K being hollowed, so'as to maintain its position on the bolt, slipping' round on it as the leg is Aflexed or extended, the bolt being rigidly secured lto ,the side pieces or metallic straps which forni the extreme upper point of the leg, vwhile the'bridge-pieceKissecured at one end in the frame ot' the thigh, and at the other oscilla-tes around the axis of articulation. The other tendon, i, passing' downwardly from the muscle I, is bifurcated, and the two tendons pass down in front ot' the axle-joint, traverse passages through the foot L, and receive their inferior attachment in the toc-piece M. The ham-strings N N are intended'to check the forward motion ofthe leg relatively to the thigh, and to prevent the anterior upper edge ot' the leg from striking the rounded end or termination ofthe thigh-piece. These strings NN have but little'elasticity and actas checks. They are inserted at their lower ends around a. pin, 0, which is iirmly attached inside'ot' the calf of the leg. surface-grooves in the posterior lower portion of the thigh, and are inserted through holesin the frame G and secured. These strings or tendons are capable of being removed by the wearer as often as'required, and ot' being adjusted with facility, so that any slackness or 'too great rigidity may be readily remedied.

The foot Lis secured to the leg by means of a ball-and-socket joint, which admits ot' a rolling motion or certain amount of rotation around any horizontal'axial line, but none around a'vertical axial line.- This limitation forward side ot' the socket, in which the ball The amount or degree of rotation described after I have spoken of the way in which the ball, which is thus socketed in the foot, is secured to the leg.' y

Q is apla-te, and Q a bridge-piece connecting said plate Q with a similar one on the other side of the leg. These plates are rigidly and very firmly secured to the frame of the leg, as the weight of the body is, of course, frequently thrown upon this part.

The 'ball P has on its `upper surface a neck,

Passing upward they occupy p, with a flange upon which the bridge Q is clamped by the set-screw R.

The interior of the socket Sl and the recess on its side nre-lined'with leather orotlher suitable yielding material, by which the required degree of rigidity is attained, whichwill enable the parts to work smoothly and avoid all the sudden jerking motions, which are unpleasant, unnatural, and deceptive totlie wearer, inasmuch as he naturally does nt expect to have to meet so quicka return motion.

The amount of friction ofthe joint, which, as in the knee, prevents the sudden return of the parts-to their relative normal position, asit may be called, is regulated in the anklejoint bythe innountot'packing material which invests the ball in the socket.

The ultimate limitof the rotation ol' the ball in its socket might be said to be the collision of the parts on the end of the leg and the upper surface of the foot, or ot' the bridge Q or flange on the neck p, with the upper surface of thefoot; but so great a motion is not desirable t'or several reasonsone is thatI it would pinch the clothing, and another is that it would bruise the parts, by means of elastic attachments consisting, tirst, of the extensor-spring I and its tendons, the forks ot' which extend into the foot, as has been described, and secondly, of the heelcord orl tendo Achilles T, which receives its lower insertion in the heel at T and its upper insertion on a spring supported by a ledge or plate, U, whose upper side has a recess for the reception of the spring V. The recess is countersunk so as to increase its capacity to retain the spring, which, at its ultimate pressure, fills the recess. In this case the nut Z comes in contact with the ledge U, and the spring is preserved from bursting, which is a common accidentto springs of'thisgcharacter, for which no provision ot' this kind is made.

The heel-cord l .has a stopper, IV, upon it, which latter bears upon the under side ot' the ledge U, being slipped upon and embracingthe cord T.

The end of' the said cord is covered by a tubeor metallic casing, Y, which is riveted upon it, and a nut, Z,is, screwed upon it, so as to bear downwardly upon'the spring and draw up the cord to the required degree v of tension. as to direction of rotation is caused by the'stud i I on thoballl, which occupies `areicess onthe The purpose-ofthe stopper W is to prevent the jumping up of the parts which rest upon the ledge U when the tension upon the cord T is relaxed in the act of rising upon the ballof the foot or in throwing the weight upon the heel with the leg inclined backward! y.

The elastic connections which I have thus described, consisting of the forward spring, I, and its tendons, and the heel-spring T, act at three diit'erent points around `the vertical axis vof the ball, which is the actual point of suspension and attachment of the foot to tholeg, and are so 'adjusted as when the foot 9s not controlled by the motion of the wearer or by its'own weightjvhcn raised to an oblique po sition, or oy cont-act with the ground or other surface, to assume the position which is natural to it when the person is standing erect. This maybe called its normal position, and any deviation from this is the effect of change ot' position ot the leg, inotion, or contact with exte-- rior objects.

The toe-piece M, which receives the insertionot' the tendons i, is attached by a hinge- `ioint to thc foot L, which admits of its upward motion when the weight is thrown upon the toes, and returning under the intinence of the spring l when the pressure is removed.

I have endeavored to explain with clearness and exactitude the method of constructing my a rtiticial leg, and have detailed the adjustment of the sain e. It remains to describe the method ot'suspendingthe same from the body and holding it upward to its place, which is a very important matter and a special feature in my invention. It is ,'often the case, as experts and patients are well awarethat a leg is apt to become unsettled, and its grasp upon the stump deranged by sitting, rising, or turning upon that leg as an axis, and the features of my inveution which remain to be explained have reference to'the method ot' suspending the leg from the body.

a ,Fig. 3, is'an elastic band which is attached to the upper front part ot' the socket, and b b is a similar strap of greater length and less power attached in a. similar manner to the posterior portion ot' the fsocket. Each of these straps has a metallic keeper, c, by which thelegis suspended from the yoke which is shown detached in Fig. et.

The leg shown is a. left ieg, and thedescription of the yoke applies to it. An expert will make the necessary modifications to meet the requirements ot' an artificial right leg.

The yoke or strap ot' webbing or other snitable material consists ot' two pieces, eff, united to a strap at d, and crossing each other at g form a loop, ef, and leave ends ef which terminate in buckle-straps h j respectively. This yoke is placed upon the .person as follows, recollecting that we arc speaking of the artiticial left limb: The side on which thc holestrapsrare attached being outside, the right arm is passed through the loop ef, so that the point g is behind the right scapula, and the strap e is passed over the let't .shoulder in -1'rontofthe person, is run through the keeper d'of the elastic strap a, and is then turned upward and buckeled to the strap d at a, the bandj" passing down behind the person, the strapj is passed through the keeper d of the elastic strap b, and being passed upward is buckled'to the strap g at It'.

The position of the yoke on the weaneris shown in thc frontand rear views at Figs. 5 and 6.

Having described with cle-arness and precision, to the best of my ability, the construction of the artificial limb, I wish now to make a few remarks in regard to its operation, to show how the motions approximate to the natural and to contrastit with other devices previously made for the same purpose.

To begin with the superior portion, I require for the purpose of suspension a band which will not slip upon the shoulders, because in using the limb the motion ot'the shoulders may be made to assist very materially. When the artiticiallimb is thrown back (we will continue to speak ot' it asthe lei't limb for the sake of convenience) the front strap, a, is extended, and as the leg is lifted to make the forward motion it is assisted by this strap.` Any mere band over the shoulder 4without a rigid attachment at some pointwill slip back and forth with the motions of theleg and tend to slip oft' the shoulder, the remedy for which last trouble is a. band across the chest, which is disagreeable and interferes with the expansion of the chest in breathing. .lhesediftcnlties-namely, the lengthwise motion of thc band or bands across the shoulder and the sli ppingo" the shoulderare both obvia-ted by the device of the yoke, which retains the band upon the shoulder and proven ts its slipping forward when the elastic strap dis drawn out in the backward motion ot' the artificial leg. fIhe band e', as will be seen, after passing through the keeper c of the strap d, is recurved upward and attached to the lwer angle otthe loop ef, passing across the abdomeu,-so as to prevent lateral displacement ot' the leg, maintaining the keeper c at substantially the saine position at all times, the elasticity being resident in the strap d.

The same remarks apply in substance to the posterior support o'f the leg, which is by means of the strap j" j, it being recurved on itselfand buckled to K. Its point of suspension may be said to bc at g, which is practically rigid, being sustained bythe band e and by the loop ef.

The elastic strap d is shorter and more powerful than 1), tor this reason: When the artieial limb is thrown back the foot is in contact with the ground, and the forward motion ot' thc body assists in detiectng the limb to therear; but when it is raised it is desirable to assist the stump in throwing` the limb'forward, as it derives no assistance in its motion as in the former action, but depends upon an actualmuscularexertion. The counterbalancing strength of the spring a has the eiiect of assisting thisf'orward motion ot' thelimb. The object is as nearly as possible to make the position ofthe anterior and posterior keepers c and c rigid, the tieiiibility residing in the springs d and b.

Proceedingdownwardly in this review ofthe case, I do not think it necessary to add to what I have said in regard to the plateA B, which adjusts the cavity ot' the socket to the size of the stump, nor further specify the action and purposes of the hamstrings; but I will explain the adaptation and peculiar action of the cXtensor-spring, which induces or influences the forward ymot-ion of the leg proper, which is defined to be the portion included between the knee and the ankle.

Here I wish to say that itis a common fault in artiliciallowerlimbs so to arrange the spring at the kneefjoint that when the artiticial'leg is thrown forward lit tends' to bend and compels v a sudden rearward motion of the stump as soon 'as the foot touches the ground* to arrest the tendency to'fleicy It will be seen thatvas the superior insertion of the eXtensor-spriug is at 'a spring of suicient strength for the 'axlejoint were attached immediately to the-frame G at it would make a stiif knee. It is necessary, therefore, to attach it in such a way .that its power shall be applied to the extent required, andby inserting it into the bridgepiece K, which has a frictionall bearing upon the bolt F and a moving 4bearing aty, the bridge-piece K becomes a lever of the 'third class, with the fulcrnmou the bolt, the end of the movinglever at y being in the anterior portion of the frame Gr. The pressure. of the bridge on the bolt, under the tension ot the spring, equalzes the motionA and makes a smooth noiseless movement of the leg, and

avoids the jarring, twitching, or Hopping incident 'to other artificial limbs, by which they are so readily detected asartilicial. aim to approximate as nearly as possible to vigorousnature', and not to thel convulsive or spasmodic action of 4partial paralysis. The

spring, being attached-near thefulcrum, utilizes for t'ue ptn poses of the knee-joint the great strength of spring, with but little elongation of the latter. When the leg is thrown forward in walking and the sole otl the foot is placed upon the ground it increases the tension of the spring, so as to stii'e'n the knee-joint at the point ot' time when it is required, and as the body in moving forward brings the leg to a vertical position this additional tension is relaxed. The point of rest of the springs is when the limb is at right angles to the sole ot ,the ioo't, which l have called its anormal positio1'|,as it is the one which it assumes when at rest, and'not ilexed by its weight by being held in an oblique or horizontal position. When one ieg is crossed overthe other the weight of the leg and foot has the effect of exing the knee-joint, so as to assume a natural position.

It is m-y4 I have thus traced downward to this point the peculiar operation of my artificial limb, and 1 believe I have shown with sucient clearness the remaining portions involved in the. structure and operation of the ankle and foot with the springs bywhich those motions are regulated,induced, or limited.

Having thus fully, clearly, and exactly described the nature, construction, and operation ofA my improvement in artificial legs, what I cla-1m therein as new, and desire to secure by Letters' Patent, is-

1. The adjustable pad B or plate within the socket, for the purpose of adapting the capacity of the socket to the stump, substantially as set forth.`

.2. :The bridge-piece K, which isvsupported upon the frame G and upon the bolt F, and affording the superior point of attachment for t-he eXtensor-spring I i! i, substantially as described.

3. The hamstrings N N, arranged substantially as described, and attached to the posteriorportions ot' the thigh and leg, to act as checks to the forward motion of the leg, in.

combination with the arrangement for adjusting'their tension. y

4. The eXtensor-spring, consisting ot' the muscularorspring portion l, the tendon z", and the bifurcated. tendon fi, the insertion of the upper tendon bcingat the bridge-piece K,which bears upon the knee-bolt, and the lowerinsertion being in the toe-piece, substantially as de scribed. l

5. The construction of the anklejoiut consisting ot' the socket in the l'oot andthe ball P, attached by its neck, and the iron frame Q Q to `the leg, and `having a stud vupon it ttingl its appropriate recess in the socket in the foot, so as to prevent vibration in a'horizontal plane, while leaving the joint for free motion in vertical planes, as described.

6. The elastic straps a. I1, proportioned as to length andst-rength substantially as and for the purpose described.

7. The yoke, Fig. 4, which derives its rigidity and freedom from tendency to displace. ment from its ultimate point of axillauv attachment, from whence the straps proceed over the shoulders, so as not alone to briugthe weight upon the frame-work of the body, but also to enable the shoulders by their motion to influ- 'encc the'motcu or the aruncial'lmb.

JOHN eoNDELL Witnesses EDWARD. H. KNIGHT, Ocfrtvius KNIGHT. 

